In most cases, support is placed underneath unless the overhang is 6 inches or less. According to the Marble Institute of America, you can safely overhang granite that is 1 ¼ inches thick up to 10 inches without support. However, the cantilevered portion cannot be more than one-third the total width of the countertop.

How much overhang should a kitchen island have without support?

Different countertop materials have different requirements. Solid Surface countertops can overhang 6 inches without additional support (e.g. plywood decking). 3 cm Quartz (engineered stone) can handle a 14 inch overhangs and 3 cm Granite overhangs should not exceed a 10 inch overhang without additional support.

When should countertop overhang be supported?

When to Install Support for Quartz Countertops

Even quartz that can support up to 14 inches of overhang runs the risk of damage on your countertop. That is why you should always add supports when the overhang exceeds one-third of its total width.